Modern lasers including semiconductor lasers, gas lasers, chemical lasers, and solid state lasers utilize optical cavities consisting of two mirrors or prisms arranged to form closed optical paths of low loss, into which an amplifying medium is inserted. The amplifying medium enclosed within the optical cavity may be gaseous, liquid, crystalline, or a glassy solid. Laser oscillation will occur at specific frequencies if the gain of the medium exceeds cavity losses. Gain of the medium is dependent upon the stimulated emission rate, which is increased when population inversion is present (a necessary condition for lasing). The onset of laser oscillation is governed by threshold conditions and stabilizes at a level that depends on the saturation intensity of the amplifying medium and the reflectance of the mirrors. The beam exits the resonator via an output coupler (“OC”), e.g., a mirror with a reflectivity of less than 1 for the lasing wavelength, in a direction perpendicular to the OC mirror, thereby establishing a directed beam of light (coherent or incoherent, as the case may be). The exiting laser beam propagates in a single direction while supporting lateral and longitudinal modes indicative of the laser design and operation. Gain saturation and second order effects limit the maximum output power of conventional lasers, thereby limiting their scalability. Many applications utilize a focused laser beam, including microscopy, industrial applications (e.g., welding, cutting, and writing), and printing, among others. The minimum spot size achievable is limited by diffraction to approximately one half the wavelength of excitation.